Manual ceramics cutters generally consist of a base to support the piece of ceramic to be cut, some longitudinal guides for the movable assembly of a support on which the folding cutting-wheel handle holder is mounted, on which the cutting-wheel handle is fixed, and an actuating lever to press and move the cutting-wheel on the ceramic thus scoring the breakage or cutting line.
The cutting-wheel usually comprises a small cutting disk made of tungsten carbide which is assembled to allow for free rotation on the front end of a handle, the scoring tool conforming the set of the cutting-wheel and the handle, once assembled and fixed on the cutting-wheel handle holder in order to score the breakage or cutting line on the piece of ceramic.
Usually, the cutting-wheel handle has a cylindrical section having in its periphery a longitudinal flat part on which the end of the actuating lever shall act frontally, retaining it in the assembly position with regard to the cutting-wheel handle holder. The end of the actuating lever mentioned is found threaded on in such a way that when inserted into a hole that has been designed to this effect in the cutting-wheel handle holder, it puts pressure frontally against the longitudinal flat part of the cutting-wheel handle, immobilising it in the position of use.
When performing the scoring of a piece of ceramic, the cutting-wheel is subjected to a movement whose frequency may oscillate, according to certain parameters such as the roughness of the surface of the piece of ceramic to be scored and the speed at which the cutting-wheel advances, of between 300 and 4000 hertz.
Another aspect to be taken into account is the vibration caused by the breakage of the surface vitrified enamel layer in which the characteristic parameter is the size of the split which is produced when scoring the piece. In studies carried out on the vibration of the cutting-wheel, it has been determined that the total spectrum of possible frequencies when the cutting-wheel acts on different materials and types of operation is from approximately 300 hertz to 4 kilohertz, with a high variability at low frequencies (in the region of 1 mm) and low variability at high frequencies (in the region of 0.05 mm or less). The low frequencies propagate through the metallic elements such as the cutting-wheel handle, the actuating lever and the machine frame while the high frequencies attenuate rapidly in the elements of the machine, making them propagate through the air causing the characteristic noise that these machines make in the scoring process.
With the use of the scoring tools currently used that are composed of the cutting-wheel—handle set, a series of disadvantages arises such as: the important shortening of the service life of the cutting-wheel, the defective scoring on certain materials such as on stoneware where discontinuous scoring has sometimes been reported due to the vibration of the cutting-wheel handle, or the transmission of vibrations to the machine and operator during the scoring process.